Distance Measurement System

This application is based on and claims priority under 35 USC 119 from Japanese Patent Application No. 2024-167687 filed September 26, 2024.

The present disclosure relates to a distance measurement system.

For example, Japanese Unexamined Patent Application Publication No. 2021-153135 discloses a measurement apparatus that includes a light emitting unit including a first light emitting section that emits light toward a first region and a second light emitting section that emits light toward a second region different from the first region. The measurement apparatus further includes a light receiving unit including a first light receiving section that receives light reflected by the first region and a second light receiving section that receives light reflected by the second region. The measurement apparatus further includes an acquisition unit that acquires information on the second region from a result that the light emitted from the first light emitting section is reflected by the second region and received by the second light receiving section.

Here, there is a light emitting device in which a plurality of light sources is provided, each including a plurality of light emitting sections. It is assumed that, in each of the plurality of light sources, one light emitting section, which emits light toward one region, enters a lighting state. When the light emitting sections of the plurality of light sources are driven to enter the lighting state only once for one region, it is presumed that the influence of a deviation of the light emitting section with respect to one region increases due to the accuracy, or the like, at the time of assembly of the plurality of light sources. Therefore, when the distance is measured based on the result of reception of the light reflected by the one region, the use of the result of light reception without correction may cause a large error in the distance. Aspects of non-limiting embodiments of the present disclosure relate to reducing an error in a measured distance as compared with a case where a result of light reception is used without correction. Aspects of certain non-limiting embodiments of the present disclosure overcome the above disadvantages and/or other disadvantages not described above. However, aspects of the non-limiting embodiments are not required to overcome the disadvantages described above, and aspects of the non-limiting embodiments of the present disclosure may not overcome any of the disadvantages described above.

According to an aspect of the present disclosure, there is provided a distance measurement system including a light emitting unit in which a plurality of light sources is provided, the light sources each including a plurality of light emitting sections capable of emitting light individually, a light receiving unit that receives reflected light from the light emitting unit, and a processor configured to drive the light emitting unit so as to have a first lighting state where one light emitting section that emits light toward one region is turned on in each of the plurality of light sources provided and a second lighting state where a plurality of light emitting sections including the one light emitting section is simultaneously turned on in at least a part of the light sources, acquire a first light reception result, which is a result of light reception by the light receiving unit in a case of the first lighting state, and a second light reception result, which is a result of light reception by the light receiving unit in a case of the second lighting state, and by using the acquired first light reception result and the acquired second light reception result, perform correction processing to correct a distance to the one region measured based on the first light reception result.

An exemplary embodiment of the present disclosure will be described below in detail with reference to the accompanying drawings. The technical scope of the present disclosure is not limited to the scope described below as an exemplary embodiment. It is apparent from the description of the scope of claims that a combination of a plurality of examples and various modifications or improvements to these examples are also included in the technical scope of the present disclosure.

1 FIG. 1 is a block diagram illustrating an example of a schematic configuration of a distance measurement apparatusto which the present exemplary embodiment is applied.

1 4 5 1 1 1 The distance measurement apparatusmeasures the distance to an object based on the time from when a light emitting unitemits light to when a light receiving unitreceives the light reflected by the object. That is, the distance measurement apparatusis an apparatus that measures a distance based on the ToF method. The ToF method includes an indirect ToF (iToF) method of measuring a time from the difference between the phases of emitted light and received light and a direct ToF (dTOF) method of directly measuring a time from light emission to light reception. In the description according to the present exemplary embodiment, it is assumed that the distance measurement apparatusmeasures a distance based on the indirect ToF method. The distance measurement apparatusis an example of a distance measurement system.

1 FIG. 1 3 8 3 4 5 4 6 4 7 5 4 5 3 2 As illustrated in, the distance measurement apparatusincludes an optical deviceand a control unit. The optical deviceincludes the light emitting unitthat emits light toward a predetermined irradiation range, the light receiving unitthat receives light that is emitted from the light emitting unitand is reflected by an object existing in the irradiation range, a light emission drive unitthat drives the light emitting unit, and a light reception drive unitthat drives the light receiving unit. The configurations of the light emitting unitand the light receiving unitof the optical devicewill be described below in detail. The configuration of the light emitting deviceis illustrated in a broken line.

8 4 5 3 8 5 1 The control unitcontrols operations of the light emitting unitand the light receiving unitof the optical device. Further, the control unitacquires the result of the light reception in the light receiving unitand measures the distance from the distance measurement apparatusto the object by the ToF method based on the result of the light reception.

5 60 8 8 8 8 8 61 8 2 FIG. 2 FIG. The light receiving unitdetects an infrared ray radiated from the object existing in the irradiation range (an irradiation surfaceindescribed below). The control unitgenerates an infrared image from a detection result. The control unitdetects an infrared ray in the irradiation range and generates an infrared image continuously or intermittently at predetermined time intervals. The control unitanalyzes the acquired infrared image to determine the condition of the object in the irradiation range. As the condition of the object in the irradiation range, the control unitdetermines whether the object is a moving object that moves in the irradiation range or a still object that remains stationary. Further, as the condition of the object in the irradiation range, the control unitdetermines which irradiation section(seedescribed below) the object exists in the irradiation range. Furthermore, when the object is a moving object, the control unitdetermines, as the condition of the object in the irradiation range, the moving direction of the object in the irradiation range and the relative movement amount of the object in the irradiation range.

2 FIG. 2 FIG. 2 FIG. 2 FIG. 2 FIG. 40 4 60 4 40 60 40 60 40 4 60 4 60 4 4 is a diagram illustrating a relationship between a light emitting surfaceof the light emitting unitand an irradiation surfaceirradiated with light emitted from the light emitting unitaccording to the present exemplary embodiment. In, the left direction of the paper surface is +x direction, the upward direction of the paper surface is +y direction, the back side direction of the paper surface is +z direction, and the opposite directions thereof are -x, -y, and -z directions. In, the light emitting surfaceand the irradiation surfaceare illustrated to be shifted in the vertical direction (±y direction) of the paper surface, but in fact, the light emitting surfaceand the irradiation surfaceare arranged to face each other. In, the light emitting surfaceof the light emitting unitis located in the front side direction (-z direction) of the paper surface, and the irradiation surfaceis located in the back side direction (+z direction) of the paper surface. That is,illustrates a state where the light emitting unitemitting the light to the irradiation surfaceis viewed from the side opposite to the side from which the light emitting unitemits the light. The light emitting unitincludes, for example, one or more light emitting chips.

4 40 43 4 60 43 43 4 40 3 FIG. 2 FIG. The light emitting unitincludes the light emitting surfaceon which a plurality of vertical cavity surface emitting lasers (VCSELs)(seedescribed below) is provided. The light emitting unitemits the light toward the irradiation surfaceby the light emission of the VCSEL. The VCSELsare not illustrated in. As described below, the light emitting unitmay include the plurality of light emitting surfaces.

40 41 43 40 41 41 41 1 12 1 12 41 1 12 2 FIG. The light emitting surfaceis divided into a plurality of light emitting sectionsthat includes at least the one VCSEL. Here, as an example, the light emitting surfaceis divided into four in the x direction and three in the y direction, the twelve light emitting sectionsin total. As illustrated, when it is necessary to distinguish each of the light emitting sections, the light emitting sectionsare distinguished as light emitting sections Ato Ain order, starting from the upper left side (the end in the +x direction and the +y direction) in. In this specification, "to" indicates a plurality of constituent elements distinguished from each other by numbers and means to include the constituent elements described before and after "to" and the constituent elements with the numbers therebetween. For example, the light emitting sections Ato Ainclude the twelve light emitting sections, from the light emitting section Ato the light emitting section Ain numerical order.

41 6 41 6 43 41 43 43 41 41 1 41 43 41 43 41 41 6 41 8 41 1 12 1 FIG. 1 FIG. 2 FIG. Each of the light emitting sectionsis independently driven by the light emission drive unit(see) to perform a light emitting operation. In other words, each of the light emitting sectionsemits light when the light emission drive unitsupplies the electric power to the VCSELincluded in the light emitting section. According to the present exemplary embodiment, the VCSELemits the light with the electric power supplied to the VCSELincluded in each of the light emitting sectionsand with the supplied electric power. The amount of light accordingly emitted from each of the light emitting sectionscan be adjusted in accordance with an environment such as the brightness in the irradiation range, operations by a user of the distance measurement apparatus, etc. According to the present exemplary embodiment, the driving of the light emitting sectionrefers to the light emission by supplying the electric power to the VCSELincluded in the light emitting section, and the light emitting operation refers to the light emission of the VCSELincluded in the light emitting sectionduring a predetermined light emission period. In addition, "independently driven" refers to a state where each of the light emitting sectionsis driven to emit light. The light emission drive unitdrives each of the light emitting sectionsin response to a control signal from the control unit(see). Therefore, all the light emitting sectionsdo not necessarily emit the light at the same time, and for example, in the example of, there may be a state where the light emitting section Ais emitting the light but the light emitting section Ais not emitting the light.

60 40 40 4 4 60 60 60 40 40 40 60 60 40 2 FIG. The irradiation surfaceis a surface which is orthogonal to the direction in which the light is emitted at a certain distance in the direction (+z direction) in which the light is emitted from a centerC of the light emitting surfaceand which is irradiated with the light from the light emitting unit. In the example of, since the light emitting unitemits the light toward the +z direction, the irradiation surfacespreads in the x direction and the y direction at a certain distance in the +z direction. Here, a central axis Ax (dash-dot-dot line) passing through a centerC of the irradiation surfaceand the centerC of the light emitting surfaceis perpendicular to the light emitting surfaceand the irradiation surface. According to the present exemplary embodiment, the irradiation surfacehas a rectangular shape corresponding to the rectangular shape of the light emitting surface.

60 61 41 40 60 61 61 61 1 12 1 1 2 FIG. 2 FIG. As illustrated, the irradiation surfaceis divided into a plurality of irradiation sectionscorresponding to the light emitting sectionson the light emitting surface. In the example of, the irradiation surfaceis divided into four in the x direction and three in the y direction, the twelve irradiation sections. When the irradiation sectionsneed to be distinguished from each other, the irradiation sectionsare denoted as irradiation sections Bto Bin order, starting from the upper left side (the end in the +x direction and the +y direction) in. A light emitting section Ai to which the same number i is assigned as a certain irradiation section Bi may be referred to as the "corresponding light emitting section". For example, the light emitting section Ais a light emitting section corresponding to the irradiation section B. Conversely, the irradiation section Bi to which the same number i is assigned as the certain light emitting section Ai may be referred to as the "corresponding irradiation section".

1 12 1 12 1 2 3 4 1 2 3 4 41 61 61 41 41 61 41 61 41 61 41 61 61 60 2 FIG. The irradiation sections Bto Bare arranged in plane symmetry with the light emitting sections Ato Awith respect to the xy plane. For example, in, the arrangement of the irradiation sections B, B, B, and Bin this order in the -x direction corresponds to the arrangement of the light emitting sections A, A, A, and Ain this order in the -x direction. Each of the light emitting sectionsemits light toward the corresponding irradiation section. Each of the irradiation sectionsis irradiated with the light emitted from the corresponding light emitting section. Here, the light emitting sectionemitting the light toward the corresponding irradiation sectionmeans that the optical axis of the light emitted from each of the light emitting sectionsis directed toward the corresponding irradiation section. There is no limitation on that all of the lights emitted from the light emitting sectionsare emitted to the corresponding irradiation sections. In other words, a part of the light emitted from the certain light emitting sectionmay be emitted to the irradiation sectiondifferent from the corresponding irradiation sectionor outside the range of the irradiation surface.

3 FIG. 2 FIG. 3 FIG. 3 FIG. 3 FIG. 4 4 4 42 40 43 42 40 4 42 is a diagram illustrating an example of the light emitting unitaccording to the present exemplary embodiment. In contrast to,illustrates a state viewed from the side where the light emitting unitemits light. Therefore, in, the rightward direction of the paper surface is the +x direction, the upward direction of the paper surface is the +y direction, and the front direction of the paper surface is the +z direction. As illustrated in, the light emitting unitincludes a substrateand the light emitting surfaceon which the plurality of the VCSELsis provided. More specifically, the substrateand the light emitting surfaceare provided to overlap each other in the direction in which the light is emitted (+z direction, the front direction of the paper surface). The wiring for supplying electric power and exchanging electric signals, electronic components related to operations of the light emitting unit, and the like, may be formed on or attached to the substrate, but the description thereof is omitted.

4 41 1 12 43 40 1 12 1 12 43 41 43 41 43 3 FIG. As described above, the light emitting unitincludes the twelve light emitting sections(the light emitting sections Ato A) in which the VCSELsare arranged on the light emitting surface. As illustrated in, all the light emitting sections Ato Ahave the same size. Further, in each of the light emitting sections Ato A, the same number (seven in this example) of the VCSELsare arranged. The sizes of the light emitting sectionsand the number of the VCSELsto be arranged are not limited, and some or all of the light emitting sectionsmay have different sizes, and different numbers of the VCSELsmay be arranged.

41 4 60 The light emitted from each of the light emitting sectionsof the light emitting unitis spread in a plane perpendicular to the emission direction (the axial direction of the central axis Ax) by an irradiation lens unit (not illustrated) and is emitted to the irradiation surface. The irradiation lens unit may be an optical member such as a diffusion plate which is provided on the optical path of the light and diffuses the light by scattering or the like, a diffractive optical element (DOE) which changes the angle of the incident light and emits the light, and/or a lens.

4 FIG. 4 FIG. 2 FIG. 4 FIG. 4 FIG. 4 FIG. 50 5 60 50 60 50 60 5 50 60 5 60 5 is a diagram illustrating a relationship between the light receiving surfaceof the light receiving unitand the irradiation surfacedescribed above according to the present exemplary embodiment. In, similarly to, the leftward direction of the paper surface is the +x direction, the upward direction of the paper surface is the +y direction, the back side direction of the paper surface is the z direction, and the opposite directions thereof are -x, -y, and -z directions. In, the light receiving surfaceand the irradiation surfaceare illustrated to be shifted in the vertical direction (±y direction) of the paper surface, but in fact, the light receiving surfaceand the irradiation surfaceare arranged to face each other. In, the light receiving unit(the light receiving surface) is located on the front side direction (-z direction) of the paper surface, and the irradiation surfaceis located on the back side direction (+z direction) of the paper surface. That is,illustrates a state where the light receiving unitreceiving the light reflected from the irradiation surfaceis viewed from the side opposite to the side where the light receiving unitreceives the light.

5 50 5 4 60 60 60 50 50 60 50 50 40 60 2 FIG. The light receiving unitincludes the light receiving surfacewhich spreads in the x direction and the y direction and on which a plurality of light receiving elements (not illustrated) is arranged. Then, the light receiving unitreceives, by the respective light receiving elements, the light emitted from the light emitting unitand reflected by the object existing on the irradiation surface. A central axis Bx (dash-dot-dot line) passing through the centerC of the irradiation surfaceand a centerC of the light receiving surfaceis perpendicular to the irradiation surfaceand the light receiving surface. According to the present exemplary embodiment, the light receiving surfacehas a rectangular shape, similarly to the light emitting surface(see) and the irradiation surface.

50 51 41 40 61 60 50 51 51 51 1 12 1 1 1 2 FIG. 2 FIG. 4 FIG. 4 FIG. The light receiving surfaceis divided into a plurality of light receiving sectionscorresponding to the light emitting sections(see) of the light emitting surface(see) and the irradiation sectionsof the irradiation surface. In the example of, the light receiving surfaceis divided into four in the x direction and three in the y direction, the twelve light receiving sections. When the light receiving sectionsneed to be distinguished from each other, the light receiving sectionsare distinguished as light receiving sections Cto Cin order, starting from the upper left side (the end in the +x direction and the +y direction) in. A light receiving section Ci to which the same number i is assigned as the certain light emitting section Ai or the certain irradiation section Bi may be referred to as the "corresponding light receiving section". For example, the light receiving section Cis a light receiving section corresponding to the light emitting section Aor the irradiation section B. Conversely, the light emitting section Ai to which the same number is assigned as the certain light receiving section Ci may be referred to as the "corresponding light emitting section", and the irradiation section Bi to which the same number is assigned as the certain light receiving section Ci may be referred to as the "corresponding irradiation section".

1 12 1 12 1 2 3 4 1 2 3 4 51 4 61 4 FIG. The light receiving sections Cto Care arranged in plane symmetry with the irradiation sections Bto Bwith respect to the xy plane. For example, in, the arrangement of the irradiation sections B, B, B, and Bin this order in the -x direction corresponds to the arrangement of the light receiving sections C, C, C, and Cin this order in the -x direction. Each of the light receiving sectionsreceives the light emitted from the light emitting unitand reflected by an object existing in the corresponding irradiation section.

51 4 60 51 7 51 51 51 51 7 51 8 5 8 51 51 8 1 FIG. 1 FIG. Each of the light receiving sectionsincludes a plurality of light receiving elements that are regularly arranged. Each of the light receiving elements can receive the light emitted from the light emitting unitand reflected by an object existing on the irradiation surfaceand output an electric signal in accordance with the received light. Examples of the light receiving element may include a photodiode or a phototransistor. Each of the light receiving sectionsis independently driven by the light reception drive unit(see) to perform a light receiving operation. Here, the driving of the light receiving sectionrefers to bringing the light receiving sectioninto a state where electric charges can be accumulated in accordance with the light reception by the light receiving element, and the light receiving operation refers to the light receiving element of the light receiving sectionaccumulating electric charges in accordance with the light reception. In addition, "independently driven" refers to a state where each of the light receiving sectionsis driven so that the electric charges corresponding to the light reception can be accumulated. The light reception drive unitdrives each of the light receiving sectionsin response to a control signal from the control unit(see). The light receiving unitoutputs, to the control unit, the electric charges accumulated in the light receiving section, i.e., the electric signal corresponding to the result of light reception in the light receiving section, in accordance with a reading operation (the details will be described below) of the control unit.

5 FIG. 5 FIG. 61 60 61 64 61 1 4 5 8 9 12 1 4 8 5 9 12 is a diagram illustrating an example of the order in which the irradiation sectionsof the irradiation surfaceare irradiated. In an example of the order illustrated in, the irradiation sectionsare sequentially irradiated in the direction of an arrow. Specifically, when the irradiation sectionsare divided into an upper stage, a middle stage, and a lower stage, the irradiation sections Bto Bof the upper stage, the irradiation sections Bto Bof the middle stage, and the irradiation sections Bto Bof the lower stage are irradiated in this order. In the upper stage, the irradiation sections Bto Bare irradiated in this order. In the case of the middle stage, the irradiation sections Bto Bare irradiated in this order, which is opposite to the direction in the case of the upper stage. In the lower stage, the irradiation sections Bto Bare irradiated in this order, which is the same as the direction in the case of the upper stage.

41 4 44 61 64 51 5 61 54 64 The light emitting sectionsof the light emitting unitare driven to emit light in the order of an arrowso that the irradiation sectionsare irradiated in the order of the arrow. The light receiving sectionsof the light receiving unitare driven to receive the reflected light from the irradiation sectionsin the order of the arrowcorresponding to the arrow.

1 FIG. 8 81 82 83 81 82 83 83 81 82 81 Referring back to, the control unitincludes a central processing unit (CPU), a read only memory (ROM), and a random access memory (RAM). The CPUis an example of a processor, and realizes each function described below by loading various programs stored in the ROMor the like into the RAMand executing the programs. The RAMis a memory used as a working memory or the like of the CPU. The ROMis a memory that stores various programs to be executed by the CPU.

81 81 Here, the program executed by the CPUmay be provided in a state of being stored in a computer-readable recording medium such as a magnetic recording medium (magnetic tape, magnetic disk, and the like), optical recording medium (optical disk and the like), magneto-optical recording medium, and semi-conductor memory. In addition, the program executed by the CPUmay be provided using a communication way such as the Internet.

According to the present exemplary embodiment, an arbitrary computer executes each processing. In addition, the arbitrary computer may execute each processing by a processor as hardware, a program as software, or a combination thereof. In this case, the processor is configured to execute various types of processing according to the present exemplary embodiment in cooperation with the program, and can function as each unit or each means according to the present exemplary embodiment. In addition, the execution order of the processing by the processor is not limited to the described order, and may be appropriately changed. The arbitrary computer may be a general purpose computer, a special purpose computer, a workstation, or any other system capable of performing each processing.

The processor may be configured by one or more pieces of hardware, and the type of hardware is not limited. For example, the processor may be configured by hardware such as a central processing unit (CPU), a micro processing unit (MPU), a programmable logic device such as a field programmable gate array (FPGA), a dedicated circuit for executing specific processing such as an application specific integrated circuit (ASIC), a graphic processing unit (GPU), or a neural processing unit (NPU). Further, the type of hardware may be a combination of different types of hardware. When a plurality of pieces of hardware is configured to execute one or more processes of a certain processor, the plurality of pieces of hardware may exist in devices physically separated from each other, or may exist in the same device. In addition, according to any exemplary embodiment, the order of the processes performed by the processor is not limited to the order described above, and may be appropriately changed. The hardware is configured by an electric circuit (circuitry) in which circuit elements such as semiconductor elements are combined.

Further, the program may be software such as firmware or microcode. In addition, the program may be, for example, a program module group, and each function thereof may be realized by a processor configured to execute each function. The program may be a program code or a plurality of code segments stored in one or more non-transitory computer-readable media (e.g., storage media or other storage). The program may be divided and stored in a plurality of non-transitory computer-readable media that exist in devices physically separated from each other. The program code or the code segments may represent procedures, functions, subprograms, routines, subroutines, modules, software packages, classes, or any combination of instructions, data structures, or program statements. The program code or the code segments may be coupled to other code segments or hardware circuits by transmitting and receiving information, data, arguments, parameters, or memory contents.

8 4 6 5 7 8 5 7 8 5 7 51 51 8 51 The control unitcontrols the light emitting operation of the light emitting unitthrough the light emission drive unitand controls the light receiving operation of the light receiving unitthrough the light reception drive unit. Further, the control unitperforms a reading operation on the light receiving unitthrough the light reception drive unit. Here, the "reading operation" means that the control unitcontrols the light receiving unitthrough the light reception drive unitto output the electric signal corresponding to the result of light reception of the light receiving element in the light receiving sectionand acquires the electric signal as the result of light reception of each of the light receiving sections. The control unitaccording to the present exemplary embodiment can perform the reading operation independently for each of the light receiving sections. For example, when the certain light receiving section Ci and another light receiving section Cj perform the light receiving operation and accumulate electric charges, it is possible to perform not only the reading operation for both the light receiving section Ci and the light receiving section Cj but also the reading operation for only the light receiving section Ci.

8 61 51 8 61 1 8 5 51 1 61 60 The control unitmeasures the distance of each of the irradiation sectionsbased on the result of light reception in each of the light receiving sections. Then, the control unitcollects the results of the distance measurement in the respective irradiation sectionsand creates a distance image representing the distance between the distance measurement apparatusand the object. More specifically, the control unitperforms predetermined arithmetic processing on the four electric signals acquired from the light receiving unitas results of the four light receptions in each of the light receiving sections. Thus, the distance between the distance measurement apparatusand the object in each of the irradiation sectionsof the irradiation surfaceis calculated (distance measurement), and the distance image is created.

6 6 FIGS.A toC 6 FIG.A 6 FIG.B 6 FIG.C 6 FIG.C 6 6 FIGS.A toC 100 1 1 2 60 100 8 100 61 60 1 2 1 100 1 are diagrams illustrating a distance imageaccording to the present exemplary embodiment.is a diagram illustrating a positional relationship between the distance measurement apparatusand objects Sand S.is a diagram illustrating a state of the irradiation surface.is a diagram illustrating an example of the distance imagecreated by the control unit. The distance imageillustrated inis created as a result of distance measurement performed on all the irradiation sectionson the irradiation surface. In the example of, it is assumed that the objects Sand S(may be referred to as objects S without being distinguished from each other) remains stationary and the position relative to the distance measurement apparatusdoes not change at least during the period from the start to the completion of the distance measurement necessary for creating the distance imagein the distance measurement apparatus.

6 FIG.C 2 4 FIGS.and 6 FIG.C 6 FIG.C 100 101 41 40 61 60 51 50 100 101 60 50 101 101 1 12 As illustrated in, the distance imagehas a plurality of image sectionscorresponding to the light emitting sectionsof the light emitting surface, the irradiation sectionsof the irradiation surface, and the light receiving sectionsof the light receiving surface(see). In the example of, the distance imageincludes the twelve image sections, four of which are arranged in the right-left direction of the drawing corresponding to the ±x direction of the irradiation surfaceand the light receiving surfaceand three of which are arranged in the vertical direction of the drawing corresponding to the ±y direction. When the image sectionsneed to be distinguished from each other, the image sectionsare distinguished as image sections Dto Din order from the upper left side in.

100 40 60 50 An image section Di in the distance imageis an image obtained based on the light that is emitted from the light emitting section Ai of the light emitting surface, reflected by the object in the irradiation section Bi of the irradiation surface, and received by the light receiving section Ci of the light receiving surface. The image section Di to which the same number i is assigned as the light emitting section Ai, the irradiation section Bi, and the light receiving section Ci may be referred to as the "corresponding image section". Conversely, the light emitting section Ai to which the same number i is assigned as the image section Di may be referred to as the "corresponding light emitting section". In addition, the irradiation section Bi to which the same number i is assigned as the image section Di may be referred to as the "corresponding irradiation section", and the light receiving section Ci to which the same number i is assigned as the image section Di may be referred to as the "corresponding light receiving section".

101 100 51 100 101 1 51 Each of the image sectionsof the distance imagehas a plurality of pixels (not illustrated) associated with the plurality of light receiving elements of the corresponding light receiving section. In the distance image, the pixel value of each pixel of the image sectioncorresponds to the distance from the distance measurement apparatusto the object, which is calculated from the electric signal from each light receiving element of the light receiving section.

6 FIG.A 6 FIG.B 1 2 1 1 1 5 9 60 2 2 6 1 1 1 2 In the example illustrated in, the objects Sand Sexist at positions away from the distance measurement apparatusby certain distances. As illustrated in, the object Sin this example exists in the range extending over the irradiation sections B, B, and Bof the irradiation surface, and the object Sexists in the range extending over the irradiation sections Band B. The distance from the distance measurement apparatusto the object S(for example, about 1 m) is shorter than the distance from the distance measurement apparatusto the object S(for example, about 3 m).

6 FIG.C 6 FIG.C 100 1 1 2 2 101 1 1 5 9 5 9 100 2 2 6 2 6 100 1 2 100 1 1 1 2 1 Then, as illustrated in, in the distance image, an image S' representing the object Sand an image S' representing the object S(which may be referred to as images S' without distinction) are depicted by the pixels included in the image sections. More specifically, the image S' is depicted over the image sections D, D, and Dcorresponding to the irradiation sections B, B, and Bin the distance image, and the image S' is depicted over the image sections Dand Dcorresponding to the irradiation sections Band Bin the distance image. In this example, the pixel values (represented by hatching in) of the pixels constituting the image S' and the image S' in the distance imagemake it possible to obtain the information on the distance from the distance measurement apparatusto the object Sand the distance from the distance measurement apparatusto the object S.

100 1 100 1 Since the distance imageincludes the information on the distance between each point on the surface of the object S and the distance measurement apparatus, it may also be considered that the distance imageincludes information on the three-dimensional shape of the object S. Therefore, the distance measurement apparatusto which the present exemplary embodiment is applied can also be used for three-dimensional measurement.

7 FIG. 7 FIG. 7 FIG. 1 1 1 1 1 1 a b a a is a perspective view illustrating a schematic configuration example of the distance measurement apparatusto which the present exemplary embodiment is applied. The distance measurement apparatusillustrated inincludes at least a housingand a printed boardaccommodated in the housing. In, a part of the housingis not illustrated.

4 5 3 1 81 82 83 8 1 b b 1 FIG. The light emitting unitand the light receiving unitforming the optical deviceare mounted on the printed board. In addition, the CPU, the ROM, and the RAM(see) forming the control unitare mounted on the printed board.

7 FIG. 3 FIG. 7 FIG. 4 410 420 430 440 410 440 40 41 410 440 5 410 440 More specifically, in the configuration example illustrated in, the light emitting unitincludes four light sources,,, and. Each of the light sourcestohas the light emitting surface(see, for example,) that is divided into the plurality of light emitting sections. The light sourcestoare arranged around the light receiving unit. Althoughillustrates an example in which the four light sourcestoare provided, the number of light sources is not limited to four and, for example, two, three, or five light sources may be provided as long as the plurality of light sources is provided.

4 410 440 1 1 12 60 1 410 440 1 410 440 1 1 410 1 1 410 440 1 5 2 FIG. 2 FIG. 4 FIG. Here, in a case where the light emitting unitincludes the plurality of light sourcesto, it is assumed that for example the irradiation section Bamong the irradiation sections Bto B(for example, see) of the irradiation surfaceis irradiated with the light from the light emitting section Aof each of the plurality of light sourcesto. When the light is irradiated from the light emitting sections Aof the plurality of light sourcesto, it is possible to irradiate the irradiation section B(see) with a higher energy density, as compared to a case where the light is irradiated from the light emitting section Aof any one of the light sources, for example, the light source. Furthermore, when the irradiation section Bis irradiated with light from each of the light emitting sections Aof the plurality of light sourcesto, the exposure time of the light receiving element (not illustrated) in the light receiving section C(see) of the light receiving unitcan be shortened, which makes it possible to reduce the capture of global components that are background light. Therefore, outdoor long-range distance measurement can be performed.

61 60 410 440 51 61 61 61 41 410 440 2 FIG. However, it is difficult to match the irradiation area for, for example, the irradiation section(for example, see) of the irradiation surfaceby the plurality of light sourcestoand the light receiving area for the light receiving sectioncorresponding to the irradiation sectiondue to variations or the like at the time of assembly. For this reason, a deviation with respect to the irradiation sectionmay occur, and a distance measurement error may increase. Therefore, in the configuration adopted according to the present exemplary embodiment, distance measurement errors are suppressed even in a case where a deviation with respect to the irradiation sectionoccurs due to the light emitting sectionsof the plurality of light sourcesto. This will be described below.

4 5 4 1 410 440 410 440 4 A configuration for suppressing a distance measurement error will be described. A first mode and a second mode for the light emitting unitand the light receiving unitwill be described below. All the light sources of the light emitting unitin the distance measurement apparatusare the plurality of light sourcesto. In the lighting states of the first mode and the second mode, the four light sourcestoare simultaneously turned on. In the lighting state, at least two or more light sources are simultaneously turned on. Therefore, when all the light sources of the light emitting unitare three or more light sources, there may be a light source that is not turned on.

8 8 FIGS.A andB 8 FIG.A 8 FIG.B 8 FIG.A 8 FIG.A 4 5 1 410 440 5 4 1 410 440 1 2 12 are diagrams illustrating the first mode of the light emitting unitand the light receiving unit.illustrates a state where the single light emitting section Aof each of the plurality of light sourcestois turned on, andillustrates the light amount distribution of the light receiving section of the light receiving unitin the case of. The lighting state of the light emitting unitillustrated inis a state where the light emitting section Aof each of the plurality of light sources 410 to 440 is turned on. That is, all the four light sourcestoare turned on (four lighting). In addition, only the one light emitting section Ais turned on, and the other light emitting sections Ato Aare not turned on.

8 FIG.B 8 FIG.B 410 440 1 5 5 410 440 1 5 410 411 420 421 430 431 440 441 As illustrated in, the lights from the light sourcestoare received by the light receiving section Cof the light receiving unit. Such light reception is divided light reception performed for each light receiving section with respect to the light receiving unit. However, due to the variations at the time of assembly described above, the lights from the light sourcesto(for example, see) are received by the light receiving section Cof the light receiving unitin a deviated manner. The light of the light sourceis in a regionindicated by a dash-dot-dot line, and the light of the light sourceis in a regionindicated by a dash-dot line. The light of the light sourceis in a regionindicated by a broken line, and the light of the light sourceis in a regionindicated by a solid line. The irradiation in this case may be referred to as divided irradiation.

9 9 FIGS.A andB 9 FIG.A 9 FIG.B 9 FIG.A 9 FIG.A 4 5 1 12 410 440 5 4 410 440 1 12 410 440 are diagrams illustrating the second mode of the light emitting unitand the light receiving unit.illustrates a state where the plurality of light emitting sections Ato Aof each of the plurality of light sourcestoare turned on, andillustrates the light amount distribution of the light receiving section of the light receiving unitin the case of. The lighting state of the light emitting unitillustrated inis a state where all of the plurality of light sourcestoare turned on (four lighting). The light emitting sections Ato Aare turned on in the light sourcesto.

9 FIG.B 410 412 420 422 430 432 440 442 In the example illustrated in, the light of the light sourceis in a regionindicated by a dash-dot-dot line, and the light of the light sourceis in a regionindicated by a dash-dot line. The light of the light sourceis in a regionindicated by a broken line, and the light of the light sourceis in a regionindicated by a solid line.

1 1 12 60 1 12 60 8 9 FIGS.B andB 4 FIG. 8 FIG.A 2 FIG. 9 FIG.A 2 FIG. The light receiving section Cand the like are illustrated in, but can also be regarded as the irradiation section B1 (see) and the like. Specifically, the case illustrated inis partial lighting of the light emitting sections Ato A, and divided irradiation is performed on the irradiation surface(see). The case illustrated inis full lighting of the light emitting sections Ato A, and full irradiation is performed on the irradiation surface(see). The image acquired by full irradiation may be referred to as a full irradiation image.

1 1 1 12 410 440 410 440 410 440 8 FIG.A 9 FIG.A In this case, the irradiation section Bis an example of one region, and the light emitting section Ais an example of one light emitting section. The light emitting sections Ato Aare examples of a plurality of light emitting sections. The light sourcestoare examples of a plurality of light sources provided and are examples of at least a part of the light sources. The lighting of the light sourcestoillustrated inis an example of a first lighting state, and the lighting of the light sourcestoillustrated inis an example of a second lighting state.

4 4 410 440 410 440 410 440 8 FIG.A 9 FIG.A 8 9 FIGS.A andA 15 FIG.B Here, it is possible to switch between the first mode of the light emitting unitillustrated inand the second mode of the light emitting unitillustrated in. In the first mode and the second mode illustrated in, the four light sourcestoare turned on. That is, the number of light sources turned on in the first mode and the number of light sources turned on in the second mode are the same, but the numbers may also be different from each other. That is, any two or three light sources among the four light sourcestomay be turned on in the first mode. In addition, only one light source among the plurality of light sourcestomay also be turned on in the second mode (seedescribed below).

10 FIG. 1 FIG. 10 FIG. 9 FIG.A 9 FIG.B 6 FIG.C 410 440 8 1 12 410 440 101 1 12 102 100 103 1 12 1 12 100 is a flowchart illustrating a control example associated with lighting of the light sourcesto. The control unitperforms this control example (see). In the control example illustrated in, the light emitting sections Ato Aof the light sourcestoare turned on (see) (step S). Further, the corresponding light receiving sections Cto C(see) are operated (step S). Accordingly, the infrared image(see), which is a full irradiation image, is generated from the acquired amount of received light (step S). The light emitting sections Ato Aare simultaneously turned on, and the light receiving sections Cto Care simultaneously operated. In this case, the acquired infrared imagemay be referred to as "flash image".

1 104 410 440 105 410 440 1 106 100 1 107 8 FIG.A 8 FIG.B 6 FIG.C After the variable n is set to(step S), the light emitting sections An of the light sourcestoare turned on (step S). In this case, the light emitting sections A1 of the light sourcestoare turned on (see). Furthermore, the corresponding light receiving section C(see) is operated (step S). Accordingly, the infrared image(see) at the time of turning on the light emitting section Ais generated from the acquired amount of received light (step S).

108 12 109 12 109 105 2 2 410 440 410 440 12 3 8 FIG.A Then, the variable n is incremented by one (step S), and it is determined whether the variable n exceeds(step S). When the variable n does not exceed(No in step S), the process returns to step S. For example, when the variable n is, the light emitting sections Aof the light sourcestoare turned on (see, for example,). Then, the light emitting sections An of the light sourcestoare turned on until the variable n reachesfrom, and accordingly, the corresponding light receiving section Cn is operated.

1 12 410 440 1 12 100 100 In this way, by sequentially turning on the light emitting sections Ato Aof the light sourcestoand operating the corresponding light receiving sections Cto C, the respective infrared imagesare acquired. The sequentially acquired infrared imagesmay be referred to as "divided irradiation images". Such a divided irradiation image may be referred to as a "scanned image".

12 109 110 When the variable n exceeds(Yes in step S), a distance image is calculated from the acquired amount of received light (step S), and then the process is terminated. In this calculation, the full irradiation image is added to the divided irradiation image. This makes it possible to reduce an error in the measured distance. The divided irradiation image is an example of a first light reception result, and the full irradiation image is an example of a second light reception result.

10 FIG. 410 440 410 440 12 In the control example illustrated in, in a case where each of the plurality of light sourcestois driven to the first lighting state once each time, the plurality of light sourcestoare driven to the second lighting state once. That is, the driving is performed for the second lighting state once for everytimes the driving is performed for the first lighting state. Thus, the number of times the driving is performed for the second lighting state can be decreased, and the control burden is reduced.

Of course, there is a possible control example in which the first lighting state and the second lighting state are alternately repeated, and also a possible control example in which the second lighting state is performed once after the first lighting state is performed multiple times. In addition, either the first lighting state or the second lighting state may be performed first.

110 81 11 FIG. 11 FIG. Next, a case where correction is performed in the calculation of step Swill be described. Such a processing example is realized by processing by the CPU.is a flowchart illustrating a control example when correction is performed. The control example ofis an example of the processing to correct the distance with respect to one region.

11 FIG. 201 202 203 204 In the processing example illustrated in, the full irradiation image is acquired (step S) and, when the twelve divided irradiation images are acquired (step S), the twelve divided irradiation images are combined (step S). Accordingly, one combined image is acquired. Then, the charge amount of the combined image is subtracted from the charge amount of the full irradiation image to generate a difference image (step S).

205 The gain of the combined image is corrected by multiplying the charge amount of the combined image by the charge amount of the difference image (step S). The multiplication described here may be performed by using the charge amount of the difference image without change, or by using the charge amount of the difference image multiplied by a coefficient. This suppresses distance measurement errors. The correction data may be acquired at the time of setup or at a predetermined timing during distance measurement, and until then, the data before update may be used as a correction value.

11 FIG. 12 FIG. 12 FIG. 6 FIG.C 301 302 100 Next, a more detailed specific example of the processing example illustrated inwill be described. The value used for the gain correction described above is hereinafter referred to as "correction parameter".is a flowchart illustrating an example of processing to generate and store a correction parameter. In the specific example illustrated in, when the full irradiation image is acquired (step S), band-pass filtering is performed to remove a noise component (step S). The full irradiation image is the infrared image(see) and is obtained by visualizing the accumulated electric charges.

303 Then, the difference between the full irradiation image and the divided irradiation image is extracted for each time gate of a multi-tap image sensor (step S). More specifically, when there are six taps (power storage elements), for example, the level adjustment is performed for each of the six time gate signals, and the difference is extracted. This difference is an irradiation unevenness due to the difference between the field of view (FOV) and the field of illumination (FOI) during 12 times of divided irradiation or a difference in the charge amount due to a difference in gain of the sensor. There is no difference between the FOV and the FOI in the full irradiation image.

The taps described here are formed of different semiconductor elements. When there are variations in the six time gate characteristics, adjustment is required for each time gate. Therefore, the correction is performed for each time gate.

For further explanation, the acquired image is, for example, pixel data of 480 × 720. The frame rate can be selected in a range up to 30 fps (frames per second). When reflected light is received, an electric charge is accumulated in each pixel. When the resolution of the accumulated electric charge in one pixel is 12 bits, 4096 gradations can be expressed. In each of the six time gates, the opening order is set in a time unit.

Data of the charge amount of each pixel is acquired for each of the above-described taps. The data structure has six taps as one set.

12 FIG. 304 305 Returning back to, the description will be continued. For each of the six time gates (6 Tap), the above-described difference is normalized (step S). Then, the normalized value is stored as a correction parameter (step S). The stored correction parameter can be used for the subsequent distance measurement.

13 13 FIGS.A andB 13 FIG.A 13 FIG.B 13 13 FIGS.A andB 13 13 FIGS.A andB 13 13 FIGS.A andB are graphs illustrating a case where a distance image is calculated from a divided irradiation image.illustrates the case of the acquired divided irradiation image, andillustrates the case of the corrected divided irradiation image.illustrate average values for several frames with the vertical axis representing the distance (m) and the horizontal axis representing the X-pixel indicating the position. As an example, a case where distance measurement is performed on an object located at a distance of 6 m will be described. In, the position of 6 m is indicated by a broken line.illustrate the divided irradiation images before and after the correction, respectively.

13 FIG.A 13 FIG.B According to the divided irradiation image before correction illustrated in, the data has variations in the distance to the object in a range from 5.85 to 5.95 m. On the other hand, according to the corrected divided irradiation image illustrated in, the distance to the object is close to 6 m indicated by a broken line. This is because the inclination and the height of the distance measurement value is corrected by the correction.

4 5 5 FIG. 5 FIG. Next, a case where a part of the irradiation light from the light emitting unit(for example, see) toward the object is reflected by, for example, a highly reflective material (not illustrated) will be described. When the irradiation light is reflected by the highly reflective material, indirect light due to the highly reflective material may enter the light receiving unit(see, for example,) in addition to the reflected light from the object. Such indirect light is noise of unintended light and affects the distance measurement value. Therefore, according to the present exemplary embodiment, the following processing is performed in order to suppress the influence of the indirect light on the distance measurement value.

14 FIG. 1 FIG. 14 FIG. 5 FIG. 8 4 401 is a flowchart illustrating an example of processing including processing to suppress the influence of indirect light. This processing example is performed by the control unit(see). In the processing example illustrated in, light is emitted from the light emitting unit(see, for example,) toward the object, and it is determined whether indirect light is present in the irradiation image (step S). This determination is made by calculating the difference between the amount of received light of the full irradiation image and the amount of received light of the divided irradiation image and determining whether the difference is larger than a predetermined threshold.

4 5 5 5 5 401 401 5 FIG. 5 FIG. More specifically, it is assumed that the light emitting unit(see, for example,) conducts full irradiation and the light receiving unit(see, for example,) receives indirect light. When the light receiving unitreceives indirect light, the amount of light received by the light receiving unitincreases by the amount of the indirect light as compared with the case where the light receiving unitreceives no indirect light. Therefore, when the difference between the amount of received light of the full irradiation image and the amount of received light of the divided irradiation image is larger than the predetermined threshold, it is determined that indirect light is present in the irradiation image (Yes in step S). When the difference is not larger than the predetermined threshold, it is determined that no indirect light is present in the irradiation image (No in step S).

12 203 12 12 11 FIG. 5 FIG. The amount of received light of the divided irradiation image here may be a total value of the amounts of received light of the respective divided irradiation images in the case of being divided into, or may be the amount of received light of the combined image (see step Sof) obtained by combining the divided irradiation images as described above. In addition to the case where the number of divisions isas described above (see), a case where the number of divisions is less thanby causing a plurality of light emitting sections to emit light at the same time is also considered.

401 402 403 401 404 403 When it is determined that indirect light is present (Yes in step S), indirect light handling processing is performed (step S), a measurement ready state is set (step S), and a standby state is kept until a distance measurement instruction is received. As a result, the irradiation amount of the corresponding light emitting section is reduced in the next irradiation. When it is determined that no indirect light is present (No in step S), the processing proceeds to step Sdescribed below. When it is determined that no indirect light is present, the processing may proceed to step S, and a standby state may be kept until a distance measurement instruction is received.

1 12 81 4 FIG. 1 FIG. 1 FIG. The indirect light handling processing described here identifies a light receiving section that has indirect light among the light receiving sections Cto C(see) and reduces the irradiation amount of the light emitting section corresponding to the identified light receiving section. That is, the CPU(see) stores, in the RAM 83 (see), the information identifying the corresponding light emitting section and the information specifying the reduced irradiation amount for the identified light emitting section.

14 FIG. 401 403 401 403 404 In, steps Sto Sare preprocessing performed before the correction processing of the divided irradiation image. More specifically, there is a possible example in which steps Sto Sare omitted and the preprocessing is not performed. In such an example, the processing is performed from step Sdescribed below.

404 406 4 5 202 5 FIG. 11 FIG. When a distance measurement instruction is received, the correction processing of the divided irradiation image is performed as illustrated in steps Sto Sdescribed below. In response to the distance measurement instruction, the light emitting unitand the light receiving unit(see) are driven and controlled. Accordingly, the divided irradiation image described above is acquired (for example, see step Sin). Then, it is determined whether the divided irradiation image needs to be corrected (step S404). This determination is made based on whether the divided irradiation image satisfies a predetermined condition.

404 404 The predetermined condition described here may be, for example, a condition that the difference between the amount of received light at the center and the amount of received light at the edge is larger than a threshold when the region of the acquired divided irradiation image is divided into the center and the edge. When the difference is larger than the threshold, it is determined that correction is needed (Yes in step S), and when the difference is equal to or smaller than the threshold, it is determined that correction is not needed (No in step S). Here, the center refers to a region that does not include the edge portions of the four sides of the divided irradiation image, and the edge refers to a region of the edge portions of the four sides of the divided irradiation image. The boundary between the central region and the edge region may be uniformly determined.

The predetermined condition described here may be, for example, whether the average of the amount of received light at the center and/or the average of the amount of received light at the edge is larger than a threshold when the region of the acquired divided irradiation image is divided into the center and the edge.

404 404 301 304 405 305 406 12 FIG. 12 FIG. When it is determined in step Sthat the correction is needed (Yes in step S), correction data is generated by performing the processing illustrated in steps Sto S(see) described above (step S). The generated correction data is stored as the correction parameter described above (see step Sin). After storing the correction data, a measurement ready state is set (step S), and a standby state is kept until the subsequent distance measurement instruction is received.

410 440 410 440 1 1 12 1 410 440 410 440 1 2 12 15 15 FIGS.A andB 15 FIG.A 15 FIG.B 15 FIG.A 8 FIG.A Next, a modification of the lighting states of the light sourcestowill be described.are diagrams illustrating the lighting states of the plurality of light sourcestoaccording to a modification.illustrates a state where the single light emitting section Ais turned on, andillustrates a state where the plurality of light emitting sections Ato Ais turned on. The lighting state illustrated inis a state where the light emitting section Aof each of the light sourcestois turned on. That is, all of the four light sourcestoare turned on (four lighting). In addition, only the one light emitting section Ais turned on, and the other light emitting sections Ato Aare not turned on. In this respect, this modification is the same as the case ofdescribed above.

15 FIG.B 9 FIG.A 440 410 440 440 410 440 410 430 1 12 440 The lighting state illustrated inis a state where the light sourceamong the light sourcestois turned on. That is, the one light sourceamong the four light sourcestois turned on, and the other light sourcestoare not turned on (one lighting). The light emitting sections Ato Aare turned on in the light source. In this respect, this modification differs from the case of, which involves four lighting described above.

4 440 6 15 15 FIGS.A andB 15 FIG.A 15 FIG.B 1 FIG. In the light emitting unit, the light sourceenters the lighting states as illustrated in. In addition, the light sources 410 to 430 enter the lighting state illustrated inand do not enter the lighting state illustrated in. The driving of the lighting state according to the modification is performed by the light emission drive unit(see).

16 16 FIGS.A andB 16 FIG.A 16 FIG.B 16 FIG.A 8 FIG.A 410 440 1 1 2 5 6 1 410 440 410 440 1 2 12 are diagrams illustrating the lighting states of the plurality of light sourcestoaccording to another modification.illustrates a state where the single light emitting section Ais turned on, andillustrates a state where the plurality of light emitting sections A, A, A, and Ais turned on. The lighting state illustrated inis a state where the light emitting section Aof each of the light sourcestois turned on. That is, all of the four light sourcestoare turned on (four lighting). In addition, only the one light emitting section Ais turned on, and the other light emitting sections Ato Aare not turned on. In this respect, this modification is the same as the case ofdescribed above.

16 FIG.B 9 FIG.A 440 410 440 440 410 440 410 430 1 2 5 6 440 1 12 3 4 7 12 The lighting state illustrated inis a state where the light sourceamong the light sourcestois turned on. That is, the one light sourceamong the four light sourcestois turned on, and the other light sourcestoare not turned on (one lighting). The light emitting sections A, A, A, and Aare turned on in the light sourceamong the light emitting sections Ato A, and the other light emitting sections A, A, and Ato Aare not turned on. In this respect, this modification differs from the case of, which involves four lighting described above.

16 FIG.A 1 2 1 3 5 7 2 Althoughillustrates a case where the single light emitting section Ais turned on, a case where another single light emitting section is turned on will be described. For example, when the single light emitting section Ais turned on, the plurality of light emitting sections Ato Aand Ato Aincluding the light emitting section Ais turned on. Thus, the plurality of light emitting sections may be light emitting sections located around the single light emitting section.

16 FIG.B 440 1 12 410 440 1 12 The lighting state illustrated inindicates a state where only the light sourceis turned on and a part of the light emitting sections Ato Ais turned on, but is not limited thereto. For example, a state where the light sourcestoare turned on and a part of the light emitting sections Ato Ais turned on may be considered.

1 1 4 410 440 1 12 5 4 81 81 4 1 410 440 1 12 1 410 440 5 5 1 1 FIG. The distance measurement apparatus, which is illustrated by a solid line in, is an example of the distance measurement systemthat includes the light emitting unitin which the plurality of light sourcestois provided, each including the plurality of light emitting sections Ato Acapable of emitting light individually, the light receiving unitthat receives reflected light from the light emitting unit, and the CPU, and the CPUdrives the light emitting unitso as to have the first lighting state where the one light emitting section Athat emits light toward the one region B1 is turned on in each of the plurality of light sourcestoprovided and the second lighting state where the plurality of light emitting sections Ato Aincluding the one light emitting section Ais simultaneously turned on in at least a part of the light sourcesto, acquires the first light reception result, which is a result of light reception by the light receiving unitin the case of the first lighting state and the second light reception result, which is a result of light reception by the light receiving unitin the case of the second lighting state, and by using the acquired first light reception result and the acquired second light reception result, performs correction processing to correct the distance to the one region Bmeasured based on the first light reception result. The present disclosure is also applicable to a program and a program product.

1

A distance measurement system comprising: a light emitting unit in which a plurality of light sources is provided, the light sources each including a plurality of light emitting sections capable of emitting light individually; a light receiving unit that receives reflected light from the light emitting unit; and a processor configured to: drive the light emitting unit so as to have a first lighting state where one light emitting section that emits light toward one region is turned on in each of the plurality of light sources provided and a second lighting state where a plurality of light emitting sections including the one light emitting section is simultaneously turned on in at least a part of the light sources; acquire a first light reception result, which is a result of light reception by the light receiving unit in a case of the first lighting state, and a second light reception result, which is a result of light reception by the light receiving unit in a case of the second lighting state; and by using the acquired first light reception result and the acquired second light reception result, perform correction processing to correct a distance to the one region measured based on the first light reception result.

2

1 The distance measurement system according to ((())), wherein the processor is configured to, by using a difference between the first light reception result and the second light reception result, perform processing to correct the distance to the one region measured based on the first light reception result.

3

1 2 The distance measurement system according to ((())) or ((())), wherein the processor is configured to switch between cases where the light sources in the first lighting state and at least the part of the light sources in the second lighting state are all of the plurality of light sources or a part of the plurality of light sources.

4

3 The distance measurement system according to ((())), wherein a number of the light sources in the first lighting state is same as a number of at least the part of the light sources in the second lighting state.

5

1 4 The distance measurement system according to any one of ((())) to ((())), wherein the processor is configured to perform the correction processing when the first light reception result satisfies a predetermined condition.

6

5 The distance measurement system according to ((())), wherein the predetermined condition is that, when the first light reception result is divided into a center and an edge, a difference between the center and the edge is larger than a threshold.

7

2 The distance measurement system according to ((())), wherein the processor is configured to, when the difference exceeds a predetermined value, perform processing to reduce an influence of indirect light on the first light reception result before the distance to the one region is corrected.